While contemplating what sort of body language I could give to a robot character I’m designing in Blender 3D, I started wondering about the shrug.

I remember reading that kissing seems to have developed from the behavior of giving young offspring pre-chewed food, and sticking your tongue out at someone echoes what babies do when they don’t like what’s in their mouth. Raising your hand in greeting shows you aren’t carrying a weapon. But what’s a shrug?

According to Kensy Cooperider, Darwin had a theory, but it remains one among several.

The shrug is one of Darwin’s central illustrations of antithesis. He invites us to consider an aggressive, “indignant” posture in which the body is primed for pugilism (see below, left). Movements of the shoulders, arms, hands, head, and face are all involved. We can then go down these movements one by one, and for each consider what a movement of a “directly opposite nature” might look like. When we do this, we end up with the prototypical shrug display, which thus embodies non-aggression or non-assertiveness. Darwin provides staged photos of both the pugilistic posture (thesis) and the full-body shrug display (antithesis), which I’ve juxtaposed above for comparison.

 

So why do [we] shrug? The short answer is, I’m afraid:  ¯\_(ツ)_/¯. The origins of this familiar gesture—a candidate human universal, now enshrined in emoji and GIFs—remain elusive. At least five explanations have been put forth—Darwin’s antithesis, Givens’s crouch, Kendon’s withdrawal, Calbris’s jerk, and Main’s jumble—and none obviously wins the day. And yet, fanciful as they may seem, one or more of these explanations may well contain the seeds of an answer.